1. Field of the Invention
The present invention generally relates to a position locating method employed for wireless communications and, more particularly, to a position locating method for wireless local area network (LAN) systems.
2. Discussion of Background
The wireless LAN defined typically by the IEEE802.11 Standard is now employed widely in offices and public spaces such as hot spots due to its properties of compatibility with the Internet and fast data transfer with wide-ranged wireless media (semi-micro waves, semi-millimeter waves, infrared rays). In the wireless LAN, for example, JP-A No.264090/2001 discloses various positional information services such as “navigation services”, “town guide information services”, supplied in accordance with the positional information of terminals.
On the other hand, JP-A No.156882/2000 discloses a method for locating positions of each terminal using global position system technology (GPS) and the self-station identity (CS-ID) of each base station. In the former method, while a terminal position is located within an accuracy of about 10 meters, the subject terminal is required to have a GPS receiver. In the latter method, while there is no need to provide the terminal with a GPS receiver, the position locating accuracy is just about a distance between base stations, since the terminal position locating is done according to the CS-ID of the nearest base station when the terminal's receiving power is the maximum. In this case, the terminal will be difficult to receive such services as the “navigation services”, which requires a certain level of accuracy.